ClaudeJ1 Posted January 22, 2013 Share Posted January 22, 2013 I finally caved in to the info. from Dr. Bruce Edgar (and Don Keele) about how good EV guitar woofers (EVM 15 L and 12L) are for bass and midbass horn, because of their low Qts, light cones, and low coil inductance gets them to go higher than K woofers. Using HornResp (FREE), I have played with over 100 iterations, some of which I have not saved. This includes a Jubilee with a single 12" driver The winner is iteration #41 of a home made, straight axis horn to go with the EVM 15L's I have in my folded Peavey FH-1 horns, which are the closest thing to a LaScala bottom. I sold all my MWMs bins (I had 6) when I moved to a small condo, but now I'm in a huge room where I can go for bigger woofer horns to go with my K402's and K1133 drivers. I'm still a believer in doing a STRAIGHT axis horn as low as possible, so if you can imagine a MINI MWMs with no fold, that is what I will build. I will use the basic MWMs flare. This is the internal portion containing the back air chamber, throat, and initial horn flare. This will coupled to a 90 degree flare that opens to 4 feet wide (instead of the almost 6 feet for the MWMs "W" bin, which is designed for a 38 Hz. cutoff. Mine is about 3/4 of that and will be -6 db at 60 Hz., which will then mate perfectly with my tapped horn sub that is flat from 15-60 Hz.. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 22, 2013 Author Share Posted January 22, 2013 So here is the 56" Long Mini MWMs Bin. Less peaks and dips with a stright axis, but cuts off 20 hz. higher than a full size MWMs, which I don't need because the Tapped Horn Sub does a better job below 60 Hz. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 22, 2013 Author Share Posted January 22, 2013 this is basically a 3.5 foot horn vs. a 6 foot horn for the full single MWMs bin. The total area of the horn mouth is only about 10% smaller than the full MWMs, so relative to the horn length, which is the main determinant of the low frequency, it's a larger mouth and a wider dispersion angle higher up. The 6 db down point according to Hornresp is about 600 Hz.. So compared to a LaScala which is about a 2.6 foot horn with a 4 square foot mouth, this is a 3.5 foot horn with a 5.2 square foot mouth. Yes it will probably stick out of the corner by 6 feet but I don't care. Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted January 23, 2013 Moderators Share Posted January 23, 2013 Always wondered what a straight horn would do, interesting, good luck, wonder how it would do for PA being it would be easier to move around. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted January 26, 2013 Share Posted January 26, 2013 How does the impulse repsonse of all you're iterations compare? Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 27, 2013 Author Share Posted January 27, 2013 How does the impulse repsonse of all you're iterations compare? Haven't looked at that yet, but I'm now going to do a corner version, since my mini would stick out about 6 feet. This one uses the dead air space in the corner behind any Belle or, in my case, the FH-1 bin. It's all a compromise, now isn't it? It looks like this is the one I will build, since it's super simple. Since I have hardwood floor, I don't even have to build a full base, just a top. I only need to buy one shheet of Oak plywood for both channels since I can make the MWMs center part out of some scraps I have laying around. It looks like about 1/2 of an MWMs, now doesn't it? but it's flat to 60 Hz., and much smoother than an MWM, since it has less then 180 degree wave travel and a wider mouth for the given cutoff frequency. I will check on the impulse looked really good, but I haven't compared. I tried an unfolded Jubilee, but the MWMs modeled much better, and the EVM 15L woofer is much better and cheaper then an EVM 12L, which would work better for midbass to 1Khz anyhow. Also, the 15L needs a smaller back chamber which saves even more space by 2/3 cubic foot . Right now, I have to boost my FH-1 by quite a bit at 65-100 Hz., which is where it rolls off, like a LaScala. The FH-1 takes 10 cubic feet vs. 8 for a LaScala, but both create dead space in the corner. This horn takes 11.5 cubic feet and goes down to 60 Hz.. with nearly full use of a corner. Diagonal from 48x48x17" tall instead of 24 for the FH-1. The 17" height vs. 25" for the FH-1 will lower my stack by 8" and bring the twetter down closer to ear level. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 27, 2013 Author Share Posted January 27, 2013 So the best compromise vs. a straight axis horn is one which is NOT a bifurcated "W" bin, but with a curved sound path the doesn't turn a full 180 degrees like the MWM. Theoretically, it should have less spikes in the response than the MWM. It models ruler flat from 60-300 Hz. and is 10 db down at 42 and 900 Hz.. So if you can just imagine chopping off one side of an MWM and widening the other mouth to 90 degrees, it will be, roughly 2/3 the space of an MWM, but fit neatly into a corner, except for the small white triangle you see in the upper right. The fat gray line approximates the sound path. Quote Link to comment Share on other sites More sharing options...
Mike 585 Posted January 28, 2013 Share Posted January 28, 2013 This is a very interesting approach. I will be staying tuned and look forward to future reports. Best of luck with your efforts. Mike Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 28, 2013 Author Share Posted January 28, 2013 This is a very interesting approach. I will be staying tuned and look forward to future reports. Best of luck with your efforts. Mike Thanks Mike. I have modeled several variations on the core section of the MWM, and it appears the original "flare rate" was a very good choice. The EVM 15L woofer, championed by horn builder Dr. Bruce Edgar apprears to be a very good choice for best response to mate with the K402/K1133 driver combo and easily makes it to a 300-500 Hz. I used to have a huge Peavey Midbass horn, which is required since the older MWM drivers wer trying to put out lots of bass at 55 Hz. while sacrificing the top end, which was eventually filled in with an MSSM (Magnificent Sub Squawker Module) from 300-800 Hz.. In fact, the current MCM 4-T does the same thing. In a home environment, my design attempts to use the best traits of the MWM woofer by designing for 60 Hz. instead of 38, use a single, shorter path with a larger mouth and greater angle of coverage at at 300-500 Hz.. A 15" motor with a huge magnet, a lightweight cone, and a low inductance coil easily gets up into the midrange. I can sacrifice the low end because my Tapped Horn Sub takes care of that, so it's basically a 2/3 size MWM with a 1/2 octave band shift while using less floor space than my current LaScala-like bin. This new horn should allow me to get rid of the 8 db boost I have to use betwen 60-100 Hz. right now using the same woofer with a simpler, longer horn. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 28, 2013 Author Share Posted January 28, 2013 As I look at my diagram above, I now realize it looks like an MWM with one side chopped off, rotated 90 degrees, and cutting the remaining side open to let the bass out of a bigger mouth from a shorter length. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 28, 2013 Author Share Posted January 28, 2013 BTW, I had a taped conversation with Gary Gillum, the co-patent holder with PWK, and former (retired) Chief Engineer at Klipsch. He described to me the development process of the orignal MWM bass unit and said it was the best sounding bass they had ever done. They basically took the core, fired it into a corner and when they threw a piece of plywood over it, VOILA, the sound just jumped out at them. they just refined it from there for easy construction. Also he said they left out the triangular throat bifurcation piece that's in the all other bass horns including the Khorn, Jubilee, Belle, and LaScala because in that particular horn it didn't measure OR sound any different without it. Since I have a single path, mine doesn't need that either. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted January 29, 2013 Share Posted January 29, 2013 Yup, they sound good. Why don't you just get a couple? Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 Yup, they sound good. Why don't you just get a couple? LOL. Funny, Mark, since you and I got our 4 MWMs bins about 2 weeks apart over 5 years ago (yes time flies). Probably should have kept my last pair or even the clones, but having moved to a smaller space, there was just no room. However, without EQ and using Hornresp modeling, I get much flatter results without the 55 Hz. peak that's in all MWMs bins with either K33 or K43 drivers. I already have EVM 15L woofers in my FH1's which work well in standard MWMs, but even better in the smaller corner version that took me months to come up with. Besides, once I have the MWM core built, I can go back to full fledged MWMs clones in the future with better performance in the midbass and flatter response in the bass end. Besides, like JC did, it's more fun to do a Hornresp model and come up with a good bass horn, in my case, easier to build with only 11 pieces of wood including the standard MWMs coreas shown in my drawing. Mark, please note the twin VMPS Large subs on either side of the center LaScalas. Bass was NOT a problem. LOL. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 Evolution continued in 2008 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 Late 2008 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 2009 after I decided two MWMs per side was overkill. With only a 7-foot ceiling in basement, I needed room for the JBL 2360a's and 2446J drivers I got from Ted Nugent's brother-in-law. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 Late 2009. Height Problem???? Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 2010 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 2011 no height problem but need a sub! Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 29, 2013 Author Share Posted January 29, 2013 2012 a year ago. Finally got my 402's. Plus more efficient Tweeter driver. Don't need midbass, since the 402 goes to 300 Hz.. Add better horn lens from QSC (mini me 402) and convert to EVM 15L drivers and sell Crites 1526. Add Tapped Horn Sub. and, look at my Avatar! Quote Link to comment Share on other sites More sharing options...
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